Amp Question!

[bigdog95325]

So I have this Phoenix Gold 400.4 Tantrum amp and a JL Audio 10W7 I'm trying to get hooked up just kind of makeshift till I redo my stero. My question is what is the correct wiring and settings to bridge the rear 2 channels to power the amp? My second question is, even with the 2 channels bridged will they provide enough power for a 10W7? Thanks in advance for the help!

[carstereopro]

Originally Posted by bigdog95325

So I have this Phoenix Gold 400.4 Tantrum amp and a JL Audio 10W7 I'm trying to get hooked up just kind of makeshift till I redo my stero. My question is what is the correct wiring and settings to bridge the rear 2 channels to power the amp? My second question is, even with the 2 channels bridged will they provide enough power for a 10W7? Thanks in advance for the help!

First let me start out by telling you that I'd never recommend "half-assing" an install for any reason, PERIOD.

That being said, you have several issues here.

1. acceptable wiring for the Tantrum 400.4, will not be the correct wiring for the correct amp for the W7. If you are going to do this, I'd run 2ga now, so when you are ready for the second amp, you'll be able to run them off the same wire.

2. The Tantrum 400.4 is not recommended to run below 4ohms when bridged, and the W7 is a 3ohm woofer. This may result in "the release of the genie of the amp" or "releasing the magic smoke". (blowing of the amp)

3. the Tantrum 400.4 is only 200w/rms mono at 4ohms when bridged. The W7 is designed to run with 375-700w/rms. Under powering this sub and trying to play at any level above moderate may result in DC clipping, which will eventually result in a blown W7 voicecoil.

I'd recommend to wait until you can do it right, and only do it once.

[RacerJames666]

Amen brother! Half assing stereo bad news...can result in bmw shaped bonfires at the more extreme fuck-ups..
Getting a proper amp would be my suggestion. Something a little more ballzy in the two chan or mono area..(them JL's POUND when set right)
Good luck!

JP

[bigdog95325]

Yea, it had a JL Audio 500/1 powering it before but I don't have that anymore. I plan on redoing the whole thing when i buy a new car in the next month. I just figured having some sounds for time being would be nice but it sounds like waiting on it is the best option.

[thekalimist]

yeah i say hold out do it right cause the only thing you can get without fryin your shit is gonna crappy sound and very low levels, which kinda defeats the purpose doesnt it? and honestly what are you running such a fine driver off such a junior-grade amplifier for? i mean that will work for your components but come on man this is a w7 for christ sake it really doesnt need to see anything without a class D license...

[carstereopro]

Originally Posted by thekalimist

it really doesnt need to see anything without a class D license...

Class D is the suck.

Although they are smaller and generally more efficient than a class A/B. I don't like them for anything but High volume SPL systems.

"Class D" amplifiers tend to share the same inherent flaws.
- horrible mid and high frequency reproduction (to the point where no-manufacturer makes a highly regarded, full range class D amplifier)
- internal switching happens at FM frequencies, so inversely effects FM reception (unless you only listen to your iPod or cd's, this is the biggest issue for most class D amplifier users)
- Dead end amplifier purchase (once you buy it, you can't run anything but subs off of it)


I'd take a good quality class A/B amp any day over a class D.

[bmw528i]

Originally Posted by carstereopro

Class D is the suck.

Although they are smaller and generally more efficient than a class A/B. I don't like them for anything but High volume SPL systems.

"Class D" amplifiers tend to share the same inherent flaws.
- horrible mid and high frequency reproduction (to the point where no-manufacturer makes a highly regarded, full range class D amplifier)
- internal switching happens at FM frequencies, so inversely effects FM reception (unless you only listen to your iPod or cd's, this is the biggest issue for most class D amplifier users)
- Dead end amplifier purchase (once you buy it, you can't run anything but subs off of it)


I'd take a good quality class A/B amp any day over a class D.

Just out of curiosity, how many class A/B amplifiers can fully power a sub woofer? I currently have both a 4 channel class A/B amplifier for my mids/highs and a class D mono amplifier for my subs and I have noticed during the rare occasions I actually listen to the radio that the bass sounds odd. On the other hand in a completely unrelated topic I've been noticing a lot of the good 4 channel full range amplifiers are being built with internal crossovers. I know that you can use the internal crossover for a set of components vs. using the supplied external crossover. I know that this is pretty popular if there isn't enough room for the external crossover in a door panel but what I've been wondering is does it improve upon sound quality at all? I assume using the internal crossovers would mean one 4 channel amp would only power one set of speakers, but if it improves the sound quality I would consider using my 4 channel specifically for my front components and getting another 4 channel or possibly but unlikely opt for a 2 channel for my rear speakers. I've been confused on the purpose of built in cross overs and how they work or if they are even worth it. I just assume the built in cross overs would be better than the external cross overs supplied with a set of speakers. If you reply to this and clarify on the differences, that is if there are any, I would greatly appreciate it.

[carstereopro]

Originally Posted by bmw528i

Just out of curiosity, how many class A/B amplifiers can fully power a sub woofer?

Back in the day they were all "A" or "A/B". I used to run PPI Art series amps, (A300 & A600) and would argue that nothing today really touches them for clarity and accuracy.

Presently there many to choose from. I'm partial to anything in the Boston Acoustics line-up, and not just because I'm the rep. Every amp is stable bridged to 2 Ohm mono.

Originally Posted by bmw528i

I currently have both a 4 channel class A/B amplifier for my mids/highs and a class D mono amplifier for my subs and I have noticed during the rare occasions I actually listen to the radio that the bass sounds odd.

The internal switching happens to interfere with FM reception. This is an inherent flaw of the class-D design. Some manufacturers have addressed it, but it's still audible.

Originally Posted by bmw528i

On the other hand in a completely unrelated topic I've been noticing a lot of the good 4 channel full range amplifiers are being built with internal crossovers. I know that you can use the internal crossover for a set of components vs. using the supplied external crossover. I know that this is pretty popular if there isn't enough room for the external crossover in a door panel but what I've been wondering is does it improve upon sound quality at all?

Well, the internal x-overs are designed to run one of the following configurations:
*Hi-pass (Filters out frequencies lower than the crossover point)
*Low-Pass (Filters out frequencies higher than the crossover point)
*Bandpass (Filters out frequencies higher than a low frequency crossover point and frequencies lower than a specific crossover point at the same time)
*Subsonic (also known as an infrasonic filter, is a hi-pass x-over designed to filter out low frequencies that are either damaging to a subwoofer, or below the threshold of normal hearing, or whichever is higher of the two)

Using an electronic crossover built into an amp for a set of component drivers would require precisely setting the crossover points to allow only the bandwidth of frequencies to pass that the speaker is designed to reproduce. This is called an "Active Crossover Network".

Using a high-pass for a tweeter set at 3500hz and a bandpass for the woofer set at 3500hz low-pass and 70hz high pass may work, if the crossover points coincide with the rated bandwidth that the speakers were designed to run.

As a replacement for the passive network, it can offer superior tuning ability, superior crossover tuning, and improved amplifier efficiency and sound quality, but usually requires an amplifier with a higher crossover slope I'm afraid the 6 or 12 dB per octave of most amplifier's crossovers is insufficient.

That is why most "active" systems run external crossover networks, like Audiocontrol and Phoenix Gold (old stuff) crossover networks.

Originally Posted by bmw528i

I assume using the internal crossovers would mean one 4 channel amp would only power one set of speakers, but if it improves the sound quality I would consider using my 4 channel specifically for my front components and getting another 4 channel or possibly but unlikely opt for a 2 channel for my rear speakers. I've been confused on the purpose of built in cross overs and how they work or if they are even worth it. I just assume the built in cross overs would be better than the external cross overs supplied with a set of speakers. If you reply to this and clarify on the differences, that is if there are any, I would greatly appreciate it.

The internal amplifier crossover is sufficient to filter the low frequencies from a component speaker, and mid and high frequencies from a subwoofer, but not generally good enough to replace the crossover of a high-end component speaker. For that I'd recommend an external electronic crossover.

[bmw528i]

Thank you for clearing that up. I remember reading some of that stuff I mentioned somewhere and it didn't make much sense to toss the provided cross-overs because they are obviously built for the components they come with. Additionally, the one thing about my system that is pissing me off is my P.O.S. deck with 2 outs and they are both front and rear hpf. I do have a sub and it doesn't sound nearly as good as it should because of this. Fortunately, I've convinced my family to help me pay for a new head-unit for Christmas. I've been looking at the Alpine IVA-D105 and I really like it. I don't need the navigation so I don't want my family or me paying any more than I really have to. At least with a dedicated sub output I know my w6 will sound the way it should. Again, thanks for clearing up my question, I really appreciate the effort.

[RacerJames666]

MTX TA92001
(oops..forgot we talkin a/b..MTX TA91002.....good stuff)